Portal portals that look strikingly authentic.
The Redditors in question, corttana and dahburbb, say that the "spiraling" effect of the lights is actually the unexpected result of curving the light rope they used into an oval shape. When asked by other users, the duo said they plan to building a Companion Cube storage chest to round out their personal Enrichment Center. You can see more photos of it at the source link.
*Portal Technology is a registered trademark of Aperture Science